Line boring machine



1932- H. c. SHOEMA KER LINE BORING MACHINE- Filed April 22. 1929 ings onen-gine blocks. 1 Y line boring machines t Patented Nov. 1 1932 HARRY-G. SHOEMAKER, or nannronr, ILLINQIS Bonnire ianonrnn' Application filed April a;

l The invention relates to improvements in line boring machines adapted for use in boring main bearings as well'as cam shaft bear- Inthe operation of has been a very difiieult matter to accurately" pilot the boring bar so as toobtain the desired high degree of accuracy in the boring of the bearings; there was always bound to' be a certain amount of misalignment and distor-'' .tion, despite every precaution. It is, therefore, the principal object of my invention to provide a'line boring machine having pilots specially constructed to float into exact align-' 'ment, and, furthermore, specially construct ed so as not to impose any distorting stress on the boring bar such as would tend toward misalignment, the same being, however, arranged, when finally setup, to support the boring bar rigidly for the boring operation, so that the alignment so carefullyobtained will not be destroyed, r

' 'llustrated in the accom- Theinvention 1S- -l panying drawing,-wherein Figure 1 is a bottom side plan view'ofan engine block with its crank case removed and showing my improved line boring inachin'e' set up thereon'forthe boring-Cot the main v pilots fore and aft 1n the slots.

bearings; 7 4 r V Fig. 2 is a view on a somewhat enlarged; scale taken on therline 2-2 of Fig. 1, show ing one of the brackets carrying itself-centering pilot providedin accordance with myinvention; 7 I

Fig. 3 is a sectional detail on the line 33 0fFig.2; I

Fig; 1- is a transversesection "on the line. 4- 1 ofFig. 3, and I i Fig. 5..is a horizontal section on the line -55 ofFig. 2.

The same reference numerals areiapplied to corresponding parts throughout the views.

The engine block designated by the refer ence numeral 5Ihas1nain'iend bearings at 6' and 7 and intermediate bearingsuat 8 and 9, this particular block being. a six-cylinder block. On blocks of such length the brackets shown at 10 are allmounted directly on the block, receiving boltsill' in slots 12 to fasten the same ontotheiside or crankcasefianges 929. seriainms'saets.

13 of the engine block. On shorter blocks,

however, thetwo endbrackets are usually mounted on-extension side rails, the boring barl l being ordinarily provided of enough length to accommodate as big a block as may} ever be encountered, thus permitting of the supportingof the ends thereof beyond the ends of the block especially in the case of smaller four-cylinder blocks. At least three supporting brackets 10 should be provided, so that pilots 15 will take care of the supporting of the boring bar liat the'middle and at or near the opposite ends thereof. The pilots 15 have'pilot bearings 16 on the lower ends thereof receiving the boring bar, these bearings being suitably split and having bolts 17 for contracting the sameto a sufficiently close fiton the bar-so that-the bar when turned by the hand crank 18, arranged to -be applied to either end'ot the bar,will operate withthe desired accuracy, assuming I the rest of the machine tobe properly set up.

A lock nut'19 is provided for each of the bolts 1 1'? to keep the pilot bearings in adjusted position. The pilots 15, it willbe observed, extend freely through slots 20 provided in the brackets 10, plates 21 bolted onto the brackets as at 22" serving to limit the movement of the Clamping screws 23, fitted with hand levers 24 for turning the same, are arranged to clamp the pilots against one side of the slots 20 and thus hold the same against lateral movement therein.

Assuming for the present that the pilot bearings 16 form a rigid part'of the pilots 15, or are even integral therewith, line boring machines of such type having been built and.

' operated with a fair degree of accuracy, it

will be seen that in operation the boring bar 14 may first be centered with reference'to the bearings in any suitable or preferred man ner, as, forexample, by placing two halfbushings in each of the end bearings6 and 7 andlaying the-boringbar therein withthe pilots 15 slipped onto the same at about the" positions represented in Fig 1, all of the intermediate main 'bearings'to be bored being also inserted previous to this centering of the boring bar. Following-the centering-operation the. cross-brackets 10 are set in place and arranged over their respective bolt holes on the side flanges 13, the pilots 15 being entered through the slots 20. Then all of the clamping levers 24 are tightened and the brackets 10 are bolted firmly in place. Now, it will be evident that in this bolting operation certain of the pilots 15 may have become cramped one way or anotherand may thus have imposed a distorting stress on the boring bar which would not be consistent with accurate operation. For this reason all of the clamping levers are released after the brackets have been bolted in place, so that all of the boring bar pilots can float into an. uncramped position, it being evident that the slots 20 are sufficiently large to permit the pilots 15 to fioatina fore and aft direction;

At this point it may be wellto note that thus far no provision has been described to take care-of floating of the pilot bearings in a lateral direction; where the pilot bearings form a rigid part of the pilots any lateral adjustability to prevent distortion of the boring bar has to be accommodated simply by the slots 12. The half-bushings previously referred to may now be removed from the endv bearings by simply turning them around the boring bar and withdrawing the same. then the boring bar may be withdrawn just far enough to permit one end bearing to be put in place. The other end bearing can be put into place by withdrawal of the boring bar in the opposite direction, care being taken in each case not to withdraw the bar too far such that its weight has to be earned on one pilot bearing as that would be apt to destroy the alignment; the bar is always kept in at least two pilot bearings if at all possible. The set-up of the machine is then complete for the performance of the boring operation. Bits such as that shown at 14 in Fig.3 are provided on the boring .bar Hand are arranged to be set with micrometers to .bore to the exact size desired. 'A feed screw sleeve is ordinarily provided in connection with the boring bar to feed the bar endwise at a pre determined rate. during the turning thereof.

the boring bar from the end away from the bearing being bored. Thus, when the front end bearing is being bored, the bar is cranked from therear end. andvice versa. This eliminates any likelihood of inaccuracy because of a side thrust imposed on the bar by the operation of the crank.

According to my invention, the pilot bearings16 have a universal mounting on the pilots 15 such that any twisting or lateral distortion of the boring bar caused in the bolting of the brackets 10 into place can be corrected, and also the slight, but nevertheless sufficiently appreciable, sag in the boring bar caused by the weight ofthe pilots being imposed thereon. The construction Which will now be described renders veach of the pilot bearings 16 self-centering such that the boring bar can be set up without the slightest distortion or misalignment. Referring principally to Figs. 2 to 4, it will be seen that each pilot bearing 16 has a stem 25 received in a hole 26 provided in a block 27 mounted for rocking movement laterally on a bolt 28 in the slot 29 provided in the lower end of the pilot 15. The bolt 28, it will be observed, extends freely through a half-round notch 30 provided in one side of the stem 25. The bolt 28 thusallows acertain amountof endwise movement of the stem 25 in thehole 26 as well as a certain amount of rotary movement on a substantially vertical axis. Furthermore, the mounting of the bearing in the block 27, which in turn is capable of rocking motion in a lateral plane, allows for this third kind of movement of the bearing. And,

of course, it was seenabove that the pilot 15 is itself capable of floating with. reference to the bracket 10 in a fore and aft plane. It

is, therefore, evident that every desired kind of movement is provided for, so far as each of the pilot bearings 16 is concerned. -Now, before proceeding with a description of the operation, attention is called to the fact that the bolt 28 not only provides a swivel mounting for the block 27 but is also arranged, when the nut 31 thereof is tightened, to clamp the stem 25 and block 27 firmly in any 'selfassumed position with respect to the pilot 15. For this purpose, saw-slots 26 are made in the'block 27 from either side of the hole 26 (see Fig. 5). When the nut 31 is tightened the block 27 is compressed in the vicinity of thehole 26 sufficiently to grip the stem 25 firmly, and at the same time the forked lower end of the pilot 15 is caused to close firmly V ontothe block 27 so that all of the parts re .ferred to are bound to maintain a stated relationship. The head 32 of the bolt 28, itwill be observed, fits into a recess in the side of the pilot 15 (see Fig. 3) and has a pin 33 proj ecting therefrom into a hole provided in the recessto receive the same, so that there is no danger of the bolt 28 turning when it is desired to tighten the nut 31.

In operation, the same procedure is followed as above set forth excepting that a tapered pin 3 1 is first inserted into registering holes provided in the pilot 15, block27, and

stem 25, the nut 31 also being tightened, so

that'the pilot bearing 16 is to all intents and purposes a rigid part ofthe pilot; Then the tapered pin 34 is, removed 5 and from this point on the same procedure is followed as first above described, where the pilot bearing this construction does not even impose any stress upon the boring bar. by reason of the pilot resting thereon and tending to cause'the bar to sag under the weight. When the lock nut81 at each of the pilot bearings is retight:

'ened, there is every assurance that the boring bar will turn true and perform the boring operationwith the highest, obtainable degree accuracy.

It is believed the foregoing description conveys a clear understanding of my invention 1 and of its various objects and advantages. It should be understood that while reference has been made in the foregoing description to various specific details of construction, the invention is not limited to these particular details; The appended claims have accordingly been drawn with a view to covering all legitiin'ate modifications and adaptations.

I claim:

1. Main bearing boring apparatus comprising a plurality of brackets to be secured to an inverted crank case and extending laterally thereof between adjacent main bear ings, said brackets being adjustable laterally of said crank case, one of said brackets extending above said crank case and being provided with a vertically extending slot, a

pilot bearing supporting member having a vertically extending portion positioned with-- in said slot for vertical adjustment therein, said slot being of greater width longitudinally of said crank case than the corresponding width of said portion to provide for tilting movement of said supporting member, and means to lock said member in adjusted position, said supporting member having a rectangular slot at its lower end extending laterally of said crank case, a rectangular block positioned within said slot for tilting movement laterally of said crank case and being provided with a vertically extending circular bore, a pilot bearing provided with a vertically extending shank, said shank being positioned within said bore for vertical movement and rotation about a vertical axis, and means to lock said rectangular member and said pilot bearing shank in adjusted position.

2. Main bearing. boring apparatus comprising a plurality-of brackets to be mounted on an inverted crank caseand extending laterally thereof between adjacent main bearings, said brackets being adjustable laterally of said crank case, one of said brack-' rectangular slot, a pilot bearing supporting member hav ng a' vertically extending rectangular portion positioned within said slot for vertical ad ustment therem, said slot being of greater width longitudinally of said crankcase than the corresponding width of said portion to-provide for tilting movement of said supportlngmembeniand means to lock said member in adjusted position, said supporting member having a slot at its lower end extending laterally of said crankcase," a block positioned wlthin said slot for tilting movement laterally of said crank case and being provided with a vertically extending circular bore, a pilot bearing provided with a vertically extending shank, said shank being positioned withln said bore for V6I'tl cal movement and for rotation about a vertical axis and means to lock said block and 1 in adjusted posi= surface extending longitudinally of said crank case, a pilot bearing supporting member positioned within said slot and having a flat surface corresponding to the flat surface of said slot, sai'd'slot being of great-er width in a direction longitudinally of said crank case than said supporting member, to

provide for'tilting movement of said inember, and'locking means to force the flat surface of said member against the fiat surface of said-slot to lock said memberi-n adjusted position, said supporting member having a slot at its lower end extending laterally ofv said crank case, a block positioned within said slot for tilting movement laterally of said crank case and being provided with a vertically extending circular bore, a pilot bearing provided with a vertically extending shank, said shank being positioned within said bore for vertical movement and for rotation about a vertical axis and means to lock saidblock and said pilot bearing shank in adjusted position. v

4:. Main bearing boring apparatus comprising a pluralityof brackets to be secured to an inverted crank case and extending laterally thereof between adjacent main bearings,saidbrackets being adjustable laterally of said crank case, one of said brackets extending above said crank case and being pro vided with a vertically extending slot, a pilot bearing supporting member having a vertically extending portion positioned within said slot for vertical adjustment therein, said slot being of greater width than the corresponding width of said portion to provide for tilting movement of said supporting member,

and means to lock said member in adjusted position, said supporting member having a rectangular slot at its lower end, a rectangular block positioned within said slot for tilt ing movement relative to said crank case and being providedwith a vertically extending circular bore, apilot bearing provided'with a vertically extending shank, said shank being positioned within said bore for vertical movement and rotation about a vertical axis, and

means to lock said rectangular member and said pilot bearing shank in adjusted position, the construction permitting tilting movement of the rectangular block and the supporting member in planes at-right angles to each other, longitudinally and laterally relative to the crank case. v

5. Main bearing boring apparatus comprising a plurality or" brackets to be mounted on an inverted crank case and extending laterally thereof between adjacent main bearings, said brackets being adjustable laterally of said crank case, one of said brackets extending above said crank case and being provided with a vertically extending rectangular slot, a pilot bearing supporting member having a vertically extending rectangular portion positioned within said slot for vertical adj ustment therein, said slot being of greater width than the corresponding width of said portion to provide for tilting movement of said ing'mo'vement of said member, and locking 7 means to force the flat surface of said mem ber against the flat surface of said slot to lock said member in adjusted position, said supporting member having a slot at its lower end, a block positioned within said slotfor tilting movement relative to said crank case and being provided'with a vertically extending circular bore,'a pilot'bearing provided with a vertically extending shank, said shank being positioned within said bore for vertical movement and for rotation about a vertical axis andi'neans to 'lo'ck'fsaid block and said pilot bearing shank in adjusted position, the

' HARRY C. SHOEMAKER.

supporting member, and means to lock said.

member in adjusted position, said supportmg member having a slot at 1ts lower end, a

40 block positioned within said slot for tilting movement relative to said crank case and being. provided with a vertically extending circular bore, a pilot bearing provided with a vertically extending shank, said shank being 45: positioned within said bore for vertical movement. and for rotation about a vertical axis and means to lock said block and said pilot bearing shank in adjusted position, the construction permitting tilting movement or" the w block and the supporting member in planes at right angles to each other, longitudinally and laterallyrelative to the crank case. 7

6. Main bearing boring apparatus comprising a plurality of brackets to be mounted 5 on an inverted crank case and extending laterally thereof between adjacent main bearin s said brackets bein ad'ustable laterall of said crank case, one of said brackets extending above said crank case and having a 60 "vertical slot therein, said slot having a fiat surface, a pilot bearing supporting member positioned Within said slot and having a fiat surface corresponding to the flat surface of said slot, said slot being of greater width than i said supporting member to provide for tilt- 

